1. Field of the Invention
The present invention relates to an apparatus for and a method of reading and erasing radiation image information by applying stimulating light to a stimulable phosphor sheet on which radiation image information has been recorded, photoelectrically reading light emitted from the stimulable phosphor sheet to acquire the recorded radiation image information therefrom, and applying erasing energy to the stimulable phosphor sheet to erase remaining radiation image information therefrom.
2. Description of the Related Art
Heretofore, there have been known radiation image information reading and erasing apparatus employing a stimulable phosphor sheet that stores part of radiation energy applied thereto and emits the stored radiation energy in response to stimulating light such as visible light applied thereto.
The radiation image information reading and erasing apparatus have a loading unit for loading a cassette which holds therein a stimulable phosphor sheet on which radiation image information of a subject such as a human body or the like has been recorded, a separating unit for separating the stimulable phosphor sheet from the cassette, a reading unit for applying stimulating light to the separated stimulable phosphor sheet to read the recorded radiation image information therefrom, and an erasing unit for applying erasing light to the stimulable phosphor sheet from which the radiation image information has been read, to erase remaining radiation image information from the stimulable phosphor sheet.
For example, Japanese Laid-Open Patent Publication No. 2002-156716 discloses a radiation image information reading and erasing apparatus having a separating unit, an erasing unit, and a reading unit that are arranged serially in the order named. A stimulable phosphor sheet separated from a cassette by the separating unit is fed through the erasing unit to the reading unit where recorded radiation image information is read from the stimulable phosphor sheet. Thereafter, remaining radiation image information is erased from the stimulable phosphor sheet while the stimulable phosphor sheet is being returned through the erasing unit to the separating unit.
For successively reading and erasing the radiation image information from the stimulable phosphor sheet within a short period of time, it is necessary to keep the reading unit and the erasing unit spaced a sufficient distance from each other or to place an appropriate light shield between the reading unit and the erasing unit so that erasing light will not leak into the reading unit.
However, when the reading unit and the erasing unit is spaced a sufficient distance from each other, the stimulable phosphor sheet tend to take a long time to travel therebetween, also making the apparatus large in size. Furthermore, since remaining radiation image information is erased from the stimulable phosphor sheet while the stimulable phosphor sheet is being fed, the apparatus needs to have a feed path length long enough to cover a maximum stimulable phosphor sheet size. If the light shield is employed, then it makes the apparatus complex in structure and expensive to manufacture.